非饱和上海软土水力和力学特性耦合弹塑性模拟

目前大多数非饱和土的弹塑性本构模型用非饱和击实土的试验结果进行验证，但现场其他类型的土，如沉积土经常有在非饱和状态下外部环境变化的情况。现有的非饱和土弹塑性模型是否适用于沉积土一类的现场土是需要研究的课题。进行非饱和上海第③层土的吸力控制排水排气三轴剪切试验，使用文中提出的能统一考虑非饱和土水力性状和力学性状的弹塑性本构模型，预测上述三轴试验结果，并与试验数据进行比较。比较结果显示，建立的本构模型能够很好地预测非饱和上海软土的水力和力学性质，说明该模型不仅可以适用击实土的预测，还能够很好地适用于其他类型非饱和土的水力和力学性质的模拟。

Elastoplastic modelling of coupled hydraulic and mechanical behaviour of unsaturated Shanghai soft clay

At present, most of the elastoplastic constitutive models for unsaturated soils are verified by using test results of unsaturated compacted soils. In situ, other types of the soils, such as alluvial soils, are often in the unsaturated states. Hence, it is necessary to study if the existing elastoplastic models for unsaturated soils are suitable for unsaturated alluvial soils. A series of triaxial tests on unsaturated Shanghai layer ③ soil were performed with suction being controlled. By using an elastoplastic model proposed by the first author for predicting the hydraulic and stress-strain behaviour of unsaturated soils, the model predictions were made on the tested conditions. Predicted results are compared with those obtained from drained triaxial compression tests on unsaturated Shanghai layer ③ soil during shear loading. The comparisons indicate that the model can reproduce the hydraulic and mechanical behaviours of undisturbed Shanghai soft clay very well. Therefore, the model is not only applicable to unsaturated compacted soils, but also is suitable for unsaturated alluvial soils.